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What is the highest radio frequency used for astronomy? Is it 3,438 GHz?
Hi:
What is the highest radio frequency used for astronomy? Is it 3,438 GHz? According to the link below, it is 3,438 GHz: http://books.nap.edu/openbook.php?re...=11719&page=11 Is 3,438 GHz the highest radio frequency used for astronomy? Thanks, Radium |
What is the highest radio frequency used for astronomy? Is it 3,438 GHz?
"Radium" wrote in message ps.com... Hi: What is the highest radio frequency used for astronomy? Is it 3,438 GHz? According to the link below, it is 3,438 GHz: http://books.nap.edu/openbook.php?re...=11719&page=11 Is 3,438 GHz the highest radio frequency used for astronomy? Thanks, Radium Radium As the article suggests, higher frequencies are considered as being in the infra red wavelengths of light, so 3,438 GHz can be considered to be at the upper limits of radio frequency astronomy. Visible light, ultra violet light, x-rays and gamma rays are all electromagnetic waves at higher frequencies and are also used for astronomy observations and experiments. Satellites are generally used to observe in the ultra violet, x-ray and gamma ray spectrums as these wave lengths are largely absorbed by the earth's atmosphere. Remember, there are no strict cut off frequencies where one type of electromagnetic wave becomes another type. Radio merges into infra red which merges into visible light, ultra violet, x-rays and so on. Any limits are purely arbitary ones applied by humans in order to categorise the way in which electromagnetic waves of a certain frequency can be expected to behave. Look at a colour palette. It is easy to pick out the primary colours. Everyone who isn't colour blind can pick out red, blue, green, yellow etc. But where do you draw the line to decide where red becomes green, blue or yellow? The colours slowly merge from one to another just as the characteristics of radio waves change as frequency increases. Mike G0ULI |
What is the highest radio frequency used for astronomy? Is it 3,438 GHz?
What is the highest radio frequency used for astronomy? Is it 3,438
GHz? According to the link below, it is 3,438 GHz: http://books.nap.edu/openbook.php?re...=11719&page=11 Is 3,438 GHz the highest radio frequency used for astronomy? That's very much a matter of convention. It all depends what you choose to call "radio frequency" and what you choose to call something else. As the article you cite points out, the measurements at 3438 GHz (3.438 THz) blur the lines between microwave measurements (which many would call "radio") and far-infrared measurements (which may would not call "radio frequency"). One source I see gives a frequency of 3.0 THz as the boundary between "microwave" and "infrared". That boundary point is, I believe, entirely one of human convention - there's no magical change in the behavior of the signals as you cross from one side of this frequency to the other. If you choose to treat the conventional boundary point of 3.0 THz as being significant for the purpose of your question, then one would have to say that the 3,438 GHz measurements you refer to are *not* "radio frequency" measurements, but rather "far-infrared" measurements. -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
What is the highest radio frequency used for astronomy? Is it 3,438 GHz?
"Dave Platt" wrote in message ... What is the highest radio frequency used for astronomy? Is it 3,438 GHz? According to the link below, it is 3,438 GHz: http://books.nap.edu/openbook.php?re...=11719&page=11 Is 3,438 GHz the highest radio frequency used for astronomy? That's very much a matter of convention. It all depends what you choose to call "radio frequency" and what you choose to call something else. As the article you cite points out, the measurements at 3438 GHz (3.438 THz) blur the lines between microwave measurements (which many would call "radio") and far-infrared measurements (which may would not call "radio frequency"). One source I see gives a frequency of 3.0 THz as the boundary between "microwave" and "infrared". That boundary point is, I believe, entirely one of human convention - there's no magical change in the behavior of the signals as you cross from one side of this frequency to the other. If you choose to treat the conventional boundary point of 3.0 THz as being significant for the purpose of your question, then one would have to say that the 3,438 GHz measurements you refer to are *not* "radio frequency" measurements, but rather "far-infrared" measurements. -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! I am curious here. At some point you have to switch from metallic conductors and antennas to lenses and other optics. Any idea what the highest frequency RF amplifier works at? Tam |
What is the highest radio frequency used for astronomy? Is it 3,438 GHz?
On Thu, 30 Aug 2007 14:52:12 -0700, Radium wrote:
Hi: What is the highest radio frequency used for astronomy? Is it 3,438 GHz? According to the link below, it is 3,438 GHz: http://books.nap.edu/openbook.php?re...=11719&page=11 Is 3,438 GHz the highest radio frequency used for astronomy? No. Hope This Helps! Rich |
What is the highest radio frequency used for astronomy? Is it 3,438 GHz?
In article ,
Tam/WB2TT wrote: I am curious here. At some point you have to switch from metallic conductors and antennas to lenses and other optics. Any idea what the highest frequency RF amplifier works at? Dunno about an RF amplifier per se. I do know that there have been some very interesting experiments with nanotechnology, over the past couple of years, in which tiny carbon nanotubes have been used as optical-frequency antennas. http://www.nanowerk.com/spotlight/spotid=1442.php has a brief writeup on one such. -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
What is the highest radio frequency used for astronomy? Is it3,438 GHz?
Tam/WB2TT wrote:
"Dave Platt" wrote in message ... What is the highest radio frequency used for astronomy? Is it 3,438 GHz? According to the link below, it is 3,438 GHz: http://books.nap.edu/openbook.php?re...=11719&page=11 Is 3,438 GHz the highest radio frequency used for astronomy? That's very much a matter of convention. It all depends what you choose to call "radio frequency" and what you choose to call something else. As the article you cite points out, the measurements at 3438 GHz (3.438 THz) blur the lines between microwave measurements (which many would call "radio") and far-infrared measurements (which may would not call "radio frequency"). One source I see gives a frequency of 3.0 THz as the boundary between "microwave" and "infrared". That boundary point is, I believe, entirely one of human convention - there's no magical change in the behavior of the signals as you cross from one side of this frequency to the other. If you choose to treat the conventional boundary point of 3.0 THz as being significant for the purpose of your question, then one would have to say that the 3,438 GHz measurements you refer to are *not* "radio frequency" measurements, but rather "far-infrared" measurements. -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! I am curious here. At some point you have to switch from metallic conductors and antennas to lenses and other optics. Any idea what the highest frequency RF amplifier works at? Tam I have even seen optics and electronics combined in an experimental Road radar for car control from Philips, radar output was a very small horn antenna connected to a wave guide, and in front of that they used a plexyglass condensor lens to make a narrow beam, like you do with light. Apparently those mm waves liked that plastic lens just fine. |
What is the highest radio frequency used for astronomy? Is it3,438 GHz?
In article ,
Sjouke Burry wrote: I have even seen optics and electronics combined in an experimental Road radar for car control from Philips, radar output was a very small horn antenna connected to a wave guide, and in front of that they used a plexyglass condensor lens to make a narrow beam, like you do with light. Apparently those mm waves liked that plastic lens just fine. It's also possible to use photonic crystals and quasicrystals to refract and band-process electromagnetic energy across a very wide range of frequencies... all the way from radio, through microwave, through far infrared, and into the optical spectrum. -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
What is the highest radio frequency used for astronomy? Is it3,438 GHz?
Dave Platt wrote:
... I do know that there have been some very interesting experiments with nanotechnology, over the past couple of years, in which tiny carbon nanotubes have been used as optical-frequency antennas. http://www.nanowerk.com/spotlight/spotid=1442.php has a brief writeup on one such. Let's hope, super cheap, super efficient solar panels would be great! Bye, bye power company ... Regards, JS |
What is the highest radio frequency used for astronomy? Is it 3,438 GHz?
On Aug 30, 5:25 pm, Sjouke Burry
wrote: Tam/WB2TT wrote: "Dave Platt" wrote in message ... What is the highest radio frequency used for astronomy? Is it 3,438 GHz? According to the link below, it is 3,438 GHz: http://books.nap.edu/openbook.php?re...=11719&page=11 Is 3,438 GHz the highest radio frequency used for astronomy? That's very much a matter of convention. It all depends what you choose to call "radio frequency" and what you choose to call something else. As the article you cite points out, the measurements at 3438 GHz (3.438 THz) blur the lines between microwave measurements (which many would call "radio") and far-infrared measurements (which may would not call "radio frequency"). One source I see gives a frequency of 3.0 THz as the boundary between "microwave" and "infrared". That boundary point is, I believe, entirely one of human convention - there's no magical change in the behavior of the signals as you cross from one side of this frequency to the other. If you choose to treat the conventional boundary point of 3.0 THz as being significant for the purpose of your question, then one would have to say that the 3,438 GHz measurements you refer to are *not* "radio frequency" measurements, but rather "far-infrared" measurements. -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! I am curious here. At some point you have to switch from metallic conductors and antennas to lenses and other optics. Any idea what the highest frequency RF amplifier works at? Tam I have even seen optics and electronics combined in an experimental Road radar for car control from Philips, radar output was a very small horn antenna connected to a wave guide, and in front of that they used a plexyglass condensor lens to make a narrow beam, like you do with light. Apparently those mm waves liked that plastic lens just fine. In fact, that would work fine at 10GHz, at 1GHz, and even at 1MHz, though the amount of material you'd have to use for the lens gets prohibitive at lower frequencies. It's all engineering tradeoffs. I know that "geodesic" lenses are used in some radar systems; the idea is that you have the signal travel a longer path (through a curved waveguide structure) in the center of the antenna/feed than it does toward the edges, just as in a convex lens the light in the center of the beam is slowed for a greater distance (and therefore retarded more) than the light at the outer edges. I expect the boundary between "optics" and "electronics" will blur even more than it is already as both electronics and optical technologies continue to advance. Cheers, Tom |
(OT) : It's "Radium" And His Asking Questions - DOH !
It's "Radium" And His Asking Questions - DOH !
- - - And Cross-Posting to Rec.Radio.Shortwave Again ! |
What is the highest radio frequency used for astronomy? Is it 3,438 GHz?
Apparently those mm waves liked that plastic lens just fine. In fact, that would work fine at 10GHz, at 1GHz, and even at 1MHz, though the amount of material you'd have to use for the lens gets prohibitive at lower frequencies. It's all engineering tradeoffs. I know that "geodesic" lenses are used in some radar systems; the idea is that you have the signal travel a longer path (through a curved waveguide structure) in the center of the antenna/feed than it does toward the edges, just as in a convex lens the light in the center of the beam is slowed for a greater distance (and therefore retarded more) than the light at the outer edges. I expect the boundary between "optics" and "electronics" will blur even more than it is already as both electronics and optical technologies continue to advance. Cheers, Tom Hi Tom, we've used plastic lensing since at least the late 60's for focusing mundane 4-12 GHz radio waves. Dielectric refraction was used back then to extract additional gain from dish antennas by allowing more even illumination of the dish without illuminating the area around the dish. Harris radio had a patent on it. W4ZCB |
What is the highest radio frequency used for astronomy? Is it 3,438 GHz?
In article om,
says... Hi: What is the highest radio frequency used for astronomy? Is it 3,438 GHz? According to the link below, it is 3,438 GHz: http://books.nap.edu/openbook.php?re...=11719&page=11 Is 3,438 GHz the highest radio frequency used for astronomy? Thanks, Radium Actually, it says 3 THz. 3.4GHz is C band, like satellite TV. Ku band sat TV is 12GHz. There are many off-the-shelf radio instruments available well above this. |
What is the highest radio frequency used for astronomy? Is it 3,438 GHz?
On Aug 30, 7:26 pm, "Harold E. Johnson" wrote:
Apparently those mm waves liked that plastic lens just fine. In fact, that would work fine at 10GHz, at 1GHz, and even at 1MHz, though the amount of material you'd have to use for the lens gets prohibitive at lower frequencies. It's all engineering tradeoffs. I know that "geodesic" lenses are used in some radar systems; the idea is that you have the signal travel a longer path (through a curved waveguide structure) in the center of the antenna/feed than it does toward the edges, just as in a convex lens the light in the center of the beam is slowed for a greater distance (and therefore retarded more) than the light at the outer edges. I expect the boundary between "optics" and "electronics" will blur even more than it is already as both electronics and optical technologies continue to advance. Cheers, Tom Hi Tom, we've used plastic lensing since at least the late 60's for focusing mundane 4-12 GHz radio waves. Dielectric refraction was used back then to extract additional gain from dish antennas by allowing more even illumination of the dish without illuminating the area around the dish. Harris radio had a patent on it. W4ZCB Hi Harold, Yep. The radar stuff I wrote about is from that era. I wouldn't be at all surprised to see mention of it from well before that; certainly we knew about the effect that makes dielectric lens action possible for RF (which is after all just a continuation of the spectrum that includes visible light) since before we knew how to generate appreciable energy at microwave frequencies. Cheers, Tom |
Radium Free "Radio Rebelde" on 11,655 kHz @ 16:57 UTC
On Aug 31, 8:34 am, John Todd wrote:
In article om, says... Hi: What is the highest radio frequency used for astronomy? Is it 3,438 GHz? According to the link below, it is 3,438 GHz: http://books.nap.edu/openbook.php?re...=11719&page=11 Is 3,438 GHz the highest radio frequency used for astronomy? Thanks, - - Radium - - Actually, it says 3 THz. - 3.4GHz is C band, like satellite TV. Ku band sat TV is 12GHz. - There are many off-the-shelf radio instruments - available well above this. HELLO - 3,438 GHz or 3.438 THz It Don't Matter. - - It Ain't Shortwave {High Frequency} Radio - - . Please remove Rec.Radio.Shortwave from "Radium's 3,483 GHz Radio Astronomy Posting and Your Replies. . Listening to Radio Rebelde right now on 11,655 kHz {Thats in the 25m Shortwave Band} @ 16:57 UTC http://www.radiorebelde.com.cu/programacion.htm Horarios y Frecuencias de Trasmisión de Radio Rebelde . Listening to the Beautiful Sounds of Latin Music and yes it sounds Astronomical to my Ears ! . Radio Rebelde - Habana Cuba - al Ritmo de la Vida http://www.radiorebelde.com.cu/ TOH News in Spanish @ 17:00 UTC . Redsun RP2100 'portable' AM/FM Shortwave Radio http://www.radiointel.com/review-redsunrp2100.htm just using the Whip Antenna S2~S3 with Fair Audio. . 17:30 UTC out ~ RHF - Twain Harte, CA -USA- . . .. . |
What is the highest radio frequency used for astronomy? Is it 3,438 GHz?
On Thu, 30 Aug 2007 17:02:02 -0700, Don Bowey wrote:
"Tam/WB2TT" wrote: ... I am curious here. At some point you have to switch from metallic conductors and antennas to lenses and other optics. Any idea what the highest frequency RF amplifier works at? It's all subject to state-of-the-art. 50 years ago 300 MHz. was complex to work with and 10 GHz. was considered way out there. Today 300 MHz is about as simple as DC and 10 GHz. is fairly straightforward to work with. I imagine that in another 50 years or less, Integrated hybrid circuits for 3 THz. will be on the shelf items for experimenters to play with. Whenever they discover neutronium, they can make ĺngstrom-sized klystrons. ;-) Cheers! Rich |
What is the highest radio frequency used for astronomy? Is it 3,438 GHz?
On Thu, 30 Aug 2007 17:16:59 -0700, Dave Platt wrote:
Tam/WB2TT wrote: I am curious here. At some point you have to switch from metallic conductors and antennas to lenses and other optics. Any idea what the highest frequency RF amplifier works at? Dunno about an RF amplifier per se. I do know that there have been some very interesting experiments with nanotechnology, over the past couple of years, in which tiny carbon nanotubes have been used as optical-frequency antennas. http://www.nanowerk.com/spotlight/spotid=1442.php has a brief writeup on one such. So, is anybody making solar panels with them yet? Thanks, Rich |
What is the highest radio frequency used for astronomy? Is it 3,438 GHz?
On Fri, 31 Aug 2007 02:25:14 +0200, Sjouke Burry wrote:
Tam/WB2TT wrote: I am curious here. At some point you have to switch from metallic conductors and antennas to lenses and other optics. Any idea what the highest frequency RF amplifier works at? I have even seen optics and electronics combined in an experimental Road radar for car control from Philips, radar output was a very small horn antenna connected to a wave guide, and in front of that they used a plexyglass condensor lens to make a narrow beam, like you do with light. Apparently those mm waves liked that plastic lens just fine. Now that you mention it, I saw something on the same principle once, but it was half a ping-pong ball filled with paraffin. :-) Cheers! Rich |
What is the highest radio frequency used for astronomy? Is it 3,438 GHz?
On Aug 30, 3:08 pm, "Mike Kaliski" wrote:
"Radium" wrote in message ps.com... Hi: What is the highest radio frequency used for astronomy? Is it 3,438 GHz? According to the link below, it is 3,438 GHz: http://books.nap.edu/openbook.php?re...=11719&page=11 Is 3,438 GHz the highest radio frequency used for astronomy? Thanks, Radium Radium As the article suggests, higher frequencies are considered as being in the infra red wavelengths of light, so 3,438 GHz can be considered to be at the upper limits of radio frequency astronomy. Visible light, ultra violet light, x-rays and gamma rays are all electromagnetic waves at higher frequencies and are also used for astronomy observations and experiments. Satellites are generally used to observe in the ultra violet, x-ray and gamma ray spectrums as these wave lengths are largely absorbed by the earth's atmosphere. Remember, there are no strict cut off frequencies where one type of electromagnetic wave becomes another type. Radio merges into infra red which merges into visible light, ultra violet, x-rays and so on. Any limits are purely arbitary ones applied by humans in order to categorise the way in which electromagnetic waves of a certain frequency can be expected to behave. Look at a colour palette. It is easy to pick out the primary colours. Everyone who isn't colour blind can pick out red, blue, green, yellow etc. But where do you draw the line to decide where red becomes green, blue or yellow? The colours slowly merge from one to another just as the characteristics of radio waves change as frequency increases. Mike G0ULI Sorry, I meant to ask whether 3,438 GHz is the highest radio frequency used to receive audio signals from outer space. I should have made my question more specific. Radio-astronomers study sounds from the sun as well as visual data. I wonder if a space station with a 3,438 GHz AM receiver could pick up any extremely-distant audio signals between 20 to 20,000 Hz [from magnetars, gamma-ray-bursts, supernovae and other high-energy but cosmic objects] after demodulating the 3,438 GHz AM carrier wave. |
What is the highest radio frequency used for astronomy? Is it3,438 GHz?
Radium wrote:
Sorry, I meant to ask whether 3,438 GHz is the highest radio frequency used to receive audio signals from outer space. I thought perhaps the O.P. was from Europe or the U.K. and that the comma in the above numeric was a substitution for a decimal point, but alas the posting IP is from So. Cal. .... Regards, Michael |
What is the highest radio frequency used for astronomy? Is it 3,438 GHz?
"Radium" wrote in message ups.com... On Aug 30, 3:08 pm, "Mike Kaliski" wrote: "Radium" wrote in message ps.com... Hi: What is the highest radio frequency used for astronomy? Is it 3,438 GHz? According to the link below, it is 3,438 GHz: http://books.nap.edu/openbook.php?re...=11719&page=11 Is 3,438 GHz the highest radio frequency used for astronomy? Thanks, Radium Radium As the article suggests, higher frequencies are considered as being in the infra red wavelengths of light, so 3,438 GHz can be considered to be at the upper limits of radio frequency astronomy. Visible light, ultra violet light, x-rays and gamma rays are all electromagnetic waves at higher frequencies and are also used for astronomy observations and experiments. Satellites are generally used to observe in the ultra violet, x-ray and gamma ray spectrums as these wave lengths are largely absorbed by the earth's atmosphere. Remember, there are no strict cut off frequencies where one type of electromagnetic wave becomes another type. Radio merges into infra red which merges into visible light, ultra violet, x-rays and so on. Any limits are purely arbitary ones applied by humans in order to categorise the way in which electromagnetic waves of a certain frequency can be expected to behave. Look at a colour palette. It is easy to pick out the primary colours. Everyone who isn't colour blind can pick out red, blue, green, yellow etc. But where do you draw the line to decide where red becomes green, blue or yellow? The colours slowly merge from one to another just as the characteristics of radio waves change as frequency increases. Mike G0ULI Sorry, I meant to ask whether 3,438 GHz is the highest radio frequency used to receive audio signals from outer space. I should have made my question more specific. Radio-astronomers study sounds from the sun as well as visual data. I wonder if a space station with a 3,438 GHz AM receiver could pick up any extremely-distant audio signals between 20 to 20,000 Hz [from magnetars, gamma-ray-bursts, supernovae and other high-energy but cosmic objects] after demodulating the 3,438 GHz AM carrier wave. Radium You are referring to "the music of the spheres". The random noises generated by very distant quasars, galaxies, supernovae and other objects. Yes it probably could and you would hear all sorts of weird pops, whistles and background noise. Just like at pretty much any other frequencies you care to monitor. Mike G0ULI |
(OT) : "What is the Highest Radio Frequency used for Shortwave {High Frequency) Radio ?
On Sep 1, 8:44 am, msg wrote:
Radium wrote: Sorry, I meant to ask whether 3,438 GHz is the highest radio frequency used to receive audio signals from outer space. I thought perhaps the O.P. was from Europe or the U.K. and that the comma in the above numeric was a substitution for a decimal point, but alas the posting IP is from So. Cal. .... Regards, Michael Hello Off-Topic "Radium-Lite" Cross-Posters, Since "Radium" Posted this Question to several Newsgroups and the Topic is a Non-Shortwave Radio Question that is being Cross-Posted to the Rec.Radio.Shortwave Newsgroup : Let me 'morph' this Question so that it is something related to Shortwave Radio. "What is the Highest Radio Frequency used for Shortwave {High Frequency) Radio ? i want to know -cause- i have been 'radiumized' ~ RHF |
What is the highest radio frequency used for astronomy? Is it 3,438 GHz?
On 2007-08-30, Tam/WB2TT wrote:
I am curious here. At some point you have to switch from metallic conductors and antennas to lenses and other optics. Any idea what the highest frequency RF amplifier works at? I've heard of X-ray lasers. Bye. Jasen |
Hearing a Talking House on 1670 kHz with the Voice of . . .
On Sep 2, 12:29 am, Jasen Betts wrote:
On 2007-08-30, Tam/WB2TT wrote: I am curious here. At some point you have to switch from metallic conductors and antennas to lenses and other optics. Any idea what the highest frequency RF amplifier works at? I've heard of X-ray lasers. Bye. Jasen I am Hearing a Talking House on 1670 kHz with the Voice of "Randy the Radio Realitor" -aka- Randy Steigler = http://www.randysteiger.com/ |
Hearing a Talking House on 1670 kHz with the Voice of . . .
On Sep 3, 12:52 am, RHF wrote:
On Sep 2, 12:29 am, Jasen Betts wrote: On 2007-08-30, Tam/WB2TT wrote: I am curious here. At some point you have to switch from metallic conductors and antennas to lenses and other optics. Any idea what the highest frequency RF amplifier works at? I've heard of X-ray lasers. Bye. Jasen I am Hearing a Talking House on 1670 kHz with the Voice of "Randy the Radio Realitor" -aka- Randy Steigler =http://www.randysteiger.com/ . Re/Max Del Oro -in- San Luis Obispo County, CAhttp://www.deloroproperties.com/ Speaking of Astronomical - SFH : 3Br+2Ba ~ $385K . Twain Harte, CA 95383 -USA- ~ RHF . . . . This will be buried inside a completely unrelated thread, but there are lots of "low power", Part 15 100mW, devices in the MW band. There is a Military Graveyard just about 15 miles south of me that has such a transmitter for "self guided tours". I have seen/received several "talking houses" including a solar powered one that I was very tempted to visit under the cover of dark and appropriate for my own use. I have seen a few billboards with these also. Down toward Tennessee the big firworks outlets tended to use them about 8 years ago. I don't know if they are still in use cause I don't get down there these days. Regarding my hunt for the UNID 1640 station rebroadcasting A NOAA weather stream, I had assumed by content it was at or near Cave Run Lake, near Morehead KY. But we visited there Friday and no signal. I talked to the Corp of Engineers and they suggested we check in Jackson. So off we went. As we approached Jackson it was clear it was not there. But I decided to check the Jackson Airport/NOAA office to see what they knew. They were aware of the TIS stations in Winchester and Richmond that carried NOAA and were for use in the event of a nerve agent leak from the Blue Grass Army Depot in Richmond, but they knew of no station on 1640. They gave me a list of towns where there are low powered NOAA WX transmitters to check and it wasn't in any of them. On a lark we went to Richmond Yesterday and the TIS on 1610 is still only receivable right next the the emergency center. But there was a different station on 1640. This one is clearly connected with the Nerve Agent program and may be in Berea. Sooner then later I hope to locate both 1640 transmitters. I will post the main body of this under a new thread. Terry |
What is the highest radio frequency used for astronomy? Is it3,438 GHz?
Harold E. Johnson wrote:
Hi Tom, we've used plastic lensing since at least the late 60's for focusing mundane 4-12 GHz radio waves. Dielectric refraction was used back then to extract additional gain from dish antennas by allowing more even illumination of the dish without illuminating the area around the dish. Harris radio had a patent on it. J.C. Bose used dielectric lenses at 90 GHz back at the end of 19th century (that is, in the late 1800s) when doing his experiments in Calcutta. Optical techniques have been used in radio for a very, very long time. |
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